Brookfield proposes full removal of Bar Mills Dam; residents press concerns on wells, access and revegetation

Brookfield on Thursday presented a draft license surrender application for the decommissioning of the Bar Mills Dam, proposing full removal of the spillway and the Rogers Fibermill foundation while retaining the powerhouse and certain transmission structures, and invited public comment on the plan and schedule.

The proposal, introduced by Brookfield project lead Ryan Neto and the owner’s engineers from Klein Schmidt, traces a several-year process that began in 2022 after the generating station was taken offline in 2017 because of concrete and structural issues. Neto said Brookfield will submit a final surrender application to the Federal Energy Regulatory Commission (FERC) after the current public comment period; company representatives said a FERC surrender order could come in 2027, with on-the-ground removal likely in late 2027 or 2028.

Why it matters: the plan would substantially change river conditions upstream of the dam, affecting recreation, public-safety access and water-table conditions for nearby residential wells. Presenters said the canal would be left dry and revegetated, trails and a hand-carry (non-trailered) boat access site are planned behind Hollis town hall, and the current boat launch adjacent to the dam would not remain as a trailer-access ramp.

"The Barmills Dam decommissioning effort has been underway since 2022," Neto said. "We value having a strong local presence and strive to be a responsible steward in the communities where we operate." Klein Schmidt engineer Kevin Kulie described the technical scope: full removal of the visible spillway, demolition and regrading of the Rogers Fibermill foundation on the Buckton side, removal of canal headworks, and retention of the powerhouse structure and powerhouse spillway with screening and plantings.

Residents asked detailed questions about paddling safety, whether the new access would support trailered boats (it will not), and how quickly water levels would drop during removal. Engineers said removal will happen in staged work using cofferdams and that the active construction window is expected to be about six months, with two primary phases that will produce relatively quick stage changes in upstream water elevation.

On wells, Brookfield said it is collecting pre-removal well data and "is committed to making it right" for households that can demonstrate a causal impact from the dam removal. "If your well’s working really well right now, it’s [...] important to get that information to us so we can prove it was working and then evaluate any impact," Neto said.

Public commenters pressed the company to remove concrete canal liners and other unused foundations wherever practicable and to include ecological controls against invasive plants during revegetation. "If there’s anything made of cement that is not a purpose for Brookfield, it should go," one local resident said, urging the company to involve wetland biologists in revegetation planning and to prioritize native species over invasive ones.

Some attendees also questioned mapping and survey details. One participant said maps in the surrender application understate a local ledge or drop; engineers responded that certain underwater and near-dam features remain difficult to survey until the dam is removed and that the profile includes a 7–10 foot elevation change over roughly 100–130 feet in the area immediately upstream of the timber crib remnants.

Brookfield described other site changes: removal of the crane and crane house on the powerhouse roof, demolition of a small unused transmission tower adjacent to the powerhouse (while leaving the primary CMP transmission tower), and relocation or removal of the large gate panels currently visible from the bridge. For security and safety, Brookfield said cameras at sites are monitored by its river control center.

On regulatory next steps, presenters said comments on the draft surrender application are due later this summer; those comments will be included in materials submitted to FERC and in state and local permit processes. The company also said it intends to remove the flashboards in spring of the next year under a filed variance to begin progressive drawdown and revegetation work prior to construction.

Brookfield and committee members closed by encouraging written comments and noting subcommittees on wells, fire-suppression infrastructure and recreation access will continue work. The meeting ended with an adjournment after public comment.

What’s next: Brookfield urged written comments be submitted during the public comment period; FERC will review the surrender application and state/local permits will proceed in parallel. The timeline presented anticipates regulatory approvals around 2027 and construction removal in late 2027 or 2028, subject to agency decisions.